Clamp

ABSTRACT

According to an aspect of the present invention, there is provided. A clamping apparatus, comprising: a first clamp provided with: a first clamp surface; a second clamp surface; and a substantially straight shaft, the first clamp surface and second clamp surface being arranged to be moveable relative to each other along the shaft to clamp an object between the first clamp surface and the second clamp surface, at least one of the clamp surfaces being releasably fixable, and a second clamp provided on an arm which extends from the second clamp surface, the arm extending in a direction substantially perpendicular to the shaft. According to another aspect of the present invention, there is provided a method of using the clamp.

The present invention relates to a clamp and a method of using thatclamp.

For many years, the application of a facade to a newly constructedbuilding was undertaken using scaffolding. Scaffolding would be erectedaround the newly constructed building, and workers would use thescaffolding to reach appropriate places around the external surface ofthe new building to apply (or complete) the facade. However, in morerecent times, the use of scaffolding to apply a facade to a newlyconstructed building (or to refurbish and existing building) has beenreplaced with a technique known as curtain-walling. Whereas in the useof scaffolding the facade is applied from the outside of the building,using curtain-walling the facade may be applied from the inside of thebuilding and supported from the floors of the building. Curtain-wallinghas become more popular in recent years due to the increased height ofnewly constructed buildings, as well as the lack of space around newlyconstructed buildings in densely populated areas, both of which make theuse of scaffolding more difficult.

Although curtain-walling is becoming a more popular technique with whichto apply a facade to a building, the methods and apparatus used to carryout curtain-walling can be improved. For example, the use ofcurtain-walling to apply a facade to a building requires the accuratelocation and alignment of substantially U-shaped channels (oftenreferred to in the industry as Halfen channels, and generally referredto as fixing channels). Current techniques used to locate and alignthese U-shaped channels are not satisfactory, and can result inmisalignment. If the U-shaped channels are misaligned, it is difficultor impossible to apply a facade to the building using these channels. Itis often necessary to realign these U-shaped channels so that the facadecan be applied to the building using the channels. Realignment of thechannels may involve time consuming excavation of the channels fromconcrete. The time taken to realign these channels can increase the costof the building, as well as incurring delays in the construction of thebuilding which can incur further costs.

It is therefore an object of the present invention to obviate ormitigate at least some of the disadvantages mentioned above.

According to a first aspect of the present invention there is provided aclamping apparatus, comprising: a first clamp provided with: a firstclamp surface; a second clamp surface; and a substantially straightshaft, the first clamp surface and second clamp surface being arrangedto be moveable relative to each other along the shaft to clamp an objectbetween the first clamp surface and the second clamp surface, at leastone of the clamp surfaces being releasably fixable, and a second clampprovided on an arm which extends from the second clamp surface, the armextending in a direction substantially perpendicular to the shaft.

According to second aspect of the present invention there is provided amethod of clamping a fixing channel in position relative to a floor slabsub structure, comprising: moving at least one of a first clamp surfaceand a second clamp surface of a first clamp along a substantiallystraight shaft, and releasably fixing the at least one clamp surface toclamp between the first clamp surface and the second clamp surface thefloor slab sub structure and an upstand extending from the floor slabsub structure; using a second clamp which is attached to the first clampto clamp the fixing channel so that the fixing channel is parallel tothe floor slab sub structure and in a position substantiallyperpendicular to and away from the shaft.

An embodiment of the present invention will now be described by way ofexample only with reference to the accompanying drawings, in which:

FIG. 1 depicts a construction technique using scaffolding;

FIG. 2 depicts a construction technique using curtain-walling;

FIGS. 3 a to 3 c depict a method used to apply curtain-walling to abuilding;

FIGS. 4 a to 4 c illustrate problems with prior art curtain-wallingmethods and apparatus;

FIG. 5 illustrates a clamp according to an embodiment of the presentinvention; and

FIG. 6 a to 6 d illustrate use of the clamp of FIG. 5.

The above mentioned figures have not been drawn to scale. Identicalfeatures have been given identical reference numbers throughout thefigures.

FIG. 1 depicts a newly constructed building 1 having a plurality offloors 2. Erected around the outside of the building 1 is scaffolding 3.The scaffolding 3 is used by, for example, builders to apply a facade tothe building 1.

The use of scaffolding is not always desirable. If the building is of acertain height, the use of scaffolding may not be appropriate or evensafe. Furthermore, if space around the building is restricted, the useof scaffolding may not be possible. Thus, the use of curtain-walling inrecent years has become more popular.

FIG. 2 illustrates the basics of curtain-walling. FIG. 2 illustratespart of a building 1, which has a plurality of floors 2. Twocurtain-walling sections 4 are also shown. The curtain-walling sections4 are suspended from and attached to the flooring 2 of the building 1.The exact fixing mechanisms are not shown in FIG. 2. It will beappreciated that the curtain-walling sections 4 may be glazing,cladding, etc. Because the curtain-walling sections 4 are attached toand suspended from the floors 2 of the building, the curtain-wallingsections 4 may be attached without the use of scaffolding. Thecurtain-walling sections may be lifted into position by crane andattached to the building 1 by workers working on the inside of thebuilding 1. Alternatively, the curtain-walling sections 4 may bedelivered to the fixing points at the outer surfaces of the building 1from within the building itself 1.

A typical apparatus and method for fixing the curtain-walling to thesides of buildings is shown in FIGS. 3 a to 3 c. Shown in FIG. 3 a is afloor slab sub structure 2 of a building (the building is not shown inthe Figure). An upstand 5 is fixed to the floor slab sub structure 2.The upstand 5 is positioned adjacent to the outer edge of the building,and is used to restrict the flow of concrete used later in the method. Acorrugated structure 6 is located on top of the floor slab sub structure2. The corrugated structure 6 may be used to provide support soffit forthe new concrete floors of the building, or even to providereinforcement to the floors. Located above the corrugated structure 6 isa layer of metal mesh 7. The metal mesh 7 is positioned such that it issubstantially parallel to the floor slab sub structure 2. An elongatesubstantially U-shaped channel 8 is fixed to the mesh 7 by way offixings 9. Although the elongation of the substantially U-shaped channel8 cannot be directly seen from FIG. 3 a, the U-shaped channel 8 iselongate in that it extends into and out of the page containing FIG. 3 a(and all Figures illustrating the U-shaped channel 8). The fixings 9 arepositioned such that the top of the U-shaped channel 8 is level with theupper point of the upstand 5 (i.e. the U-shaped channel is parallel andlevel with respect to the floor slab sub structure 2).

It can be seen from the Figure that the substantially U-shaped channel 8is not exactly U-shaped, but has inwardly facing lips. The lips are usedto prevent a fixing element from moving out of the channel when thefixing element has been appropriately positioned in the channel (asdescribed below). The substantially U-shaped channel 8 is abbreviated to‘U-shaped channel’ hereafter.

Once the construction of FIG. 3 a has been completed, concrete 10 ispoured through the metal mesh 7 up to the level of the top of theupstand 5 and the top of the U-shaped channel 8. The concrete 10 isallowed to set such that the U-shaped channel 8 is fixed in position.The U-shaped channel 8 then acts as a fixing channel for additionalstructures. In this case, the additional structures are curtain-wallingsections (or brackets for curtain walling sections).

FIG. 3 c shows how a curtain-walling section 4 may be fixed in positionrelative to the floor slab sub structure 2 of the building. A bracket 11is fixed to the U-shaped channel 8 by passing through the bracket 11 anelongate fastener 12 which is initially aligned parallel to the lengthof the U-shaped channel 8. The elongate fastener 12 may then be rotatedsuch that it extends across the width of the U-shaped channel (i.e.perpendicular to its length), such that it cannot be removed from theU-shaped channel (i.e. the lips of the channel prevent removal of theelongate fastener). The bracket 11 may then be fixed in position bysecuring the elongate fastener by way of a nut 13.

The bracket 11 is of a sufficient length to overhang the side of thebuilding and the floor slab sub structure 2. The curtain-walling section4 may be attached to the bracket, and therefore suspended from the floorslab sub structure 2, by attaching the curtain-walling section 4 to thebracket 11. The curtain-walling section can be attached to the bracket11 by way of a conventional nut and bolt arrangement 14.

FIG. 3 c shows how the curtain-walling section 4 may be satisfactorilysuspended from a floor slab sub structure 2 of a building in order toclad a building. However, the method and apparatus described withreference to FIGS. 3 a to 3 c has at least one serious deficiency. Thisdeficiency is illustrated in FIGS. 4 a to 4 c.

FIG. 4 a is generally the same as FIG. 3 a. However, in FIG. 4 a aworker has stepped onto the metal mesh 7 causing it to deform, i.e. themetal mesh is no longer horizontal and parallel to the floor slab substructure 2. A worker's boot 15 is illustrated in FIG. 4 a as an aid tounderstanding one of the possible causes of the deformation of the metalmesh 7. It can be seen from FIG. 4 a that due to the deformation of themetal mesh 7, the U-shaped channel 8 is no longer level with the floorslab sub structure 2, but is slightly tilted (i.e. misaligned).

The misaligned U-shaped channel 8 is fixed in position when concrete 10is poured in and around the U-shaped channel and allowed to set. Theactual pouring of the concrete can cause further misalignment of theU-shaped channel 8.

FIG. 4 c illustrates the theoretical situation that would arise if thecurtain-walling section 4 was fixed in position relative to the floorslab sub structure 2 and misaligned U-shaped channel 8 as described inrelation to FIG. 3 c. It can be seen in FIG. 4 c that due to themisalignment of the U-shaped channel 8, the curtain-walling section 4 isnot parallel to the sides of the upstand 5, and that it is not parallelto the side of the building. If the curtain-walling sections 4 are notparallel to the sides of the building, there could be a number ofundesirable consequences. For example, the curtain-walling sections maygive the building an appearance which is not aesthetically pleasing.More importantly perhaps, the misalignment of the curtain-wallingsections 4 may reduce the insulation on the building or even itsstructural integrity. Furthermore, if the curtain-walling sections 4were aligned as shown in FIG. 4 c, a large amount of stress and strainmay be induced in the bracket 11 and parts connecting the bracket 11 tothe curtain-walling section 4 and U-shaped element 8. These stresses andstrains may eventually cause the curtain-walling section 4 to comeloose, or at least damage the concrete 10 surrounding the U-shapedelement 8 which can also reduce the structural integrity of thebuilding.

Although in theory the problems described in relation to FIG. 4 c arepossible, in practice most builders would not attempt to fix thecurtain-walling section 4 to the U-shaped channel 8 when or if theynoticed that the U-shaped channel 8 was not aligned correctly. A morelikely scenario would be that the builders would have to chip away atthe concrete 10 surrounding the U-shaped channel 8 in order to realignit and reset it in a correct position. Whereas this course of actionwould ensure that the structural integrity of the building was notcompromised (as described earlier) realigning the U-shaped channel 8 maytake a considerable amount of time (e.g. 45 mins to 1 hour). Any delayin the construction of the curtain-walling sections may have knock ondelays for other contractors, for example electricians and decoratorswishing to commence work on the interior of the building. Such delayscan incur significant expense. It is desirable to avoid these delays andconsequential expense.

FIG. 5 illustrates a clamping apparatus 20 in accordance with anembodiment of the present invention. The clamping apparatus 20 isprovided with two clamps. A first clamp is arranged to clamp around thefloor slab sub structure 2 and upstand 5 illustrated in FIGS. 3 and 4.The first clamp comprises a first clamp surface 21 and an opposablesecond clamp surface 22. The first clamp surface 21 is fixed inposition, whereas the second clamp surface 22 is moveable relative tothe first clamp surface 21 along a threaded shaft 23 which extends fromthe first clamp surface 21 and through the second clamp surface 22. Awing nut 24 is provided adjacent to the second clamp surface 22, and isrotatable about the threaded shaft 23 to secure the clamping apparatus20 on an object (e.g. the floor slab of FIGS. 3 and 4). Any suitableclamping arrangement may be employed. For example, the second clampsurface could be fixed in position, and the first clamp surfacemoveable. Alternatively, both clamp surfaces could be moveable relativeto one another, so long as the movement is releasably fixable (i.e. thepositioning of the clamp surfaces can be fixed, but is not permanent andcan be changed).

The clamping apparatus 20 is provided with a guide rail 25. The guiderail 25 extends from the second clamp surface 22 towards and through thefirst clamp surface 21. The guide rail 25 makes the clamping apparatus20 more rigid.

The second clamp surface 22 is provided with an elongate arm 26. Theelongate arm 26 extends away from the threaded shaft 23 and issubstantially perpendicular to the threaded shaft 23. Provided on theelongate arm 26 is a second clamp. The second clamp is provided with anelongate fixing element 12. The elongate fixing element 12 is providedwith a threaded shaft 27 that extends through the elongate arm 26. Thethreaded shaft 27 and elongate fixing element 12 are fixed in positionby a wing nut 28. The wing nut 28 can be tightened to clamp the elongatefixing element 12 in position. An object can be clamped between theelongate fixing element 12 and the elongate arm 26.

When not fixed in position by the wing nut 28, the elongate fixingelement 12 may be moved along a slot provided in the elongate arm 26(the slot is not shown in FIG. 5). Once the elongate fixing element 12has been moved to an appropriate location, its position can be fixedrelative to the elongate arm 26 by tightening the wing nut 28.Repositioning of the elongate fixing element 12 can be achieved byuntightening the wing nut 28 and sliding the elongate fixing element 12along the slot provided in the elongate arm 26.

The clamping apparatus 20 can be constructed from any suitable material.For example, the clamping apparatus 20 can be constructed fromaluminium, steel, etc.

Use of the clamping apparatus 20 of FIG. 5 is shown and described inrelation to FIGS. 6 a to 6 d. FIG. 6 a shows a floor slab sub structure2. Attached to the floor slab sub structure 2 at the outer edge of thebuilding is the upstand 5. Disposed on top of the floor slab substructure 2 is a corrugated sheet 6. The floor slab sub structure 2,upstand 5 and corrugated sheet 6 are identical to those described inrelation to FIGS. 3 and 4. The clamping apparatus 20 is attached to thefloor slab sub structure 2 and upstand 5. The clamping apparatus 20 isattached by positioning the first clamp surface 21 underneath the floorslab sub structure 2 and positioning the second clamp surface 22 abovethe upstand 5. The second clamp surface 22 is moved such that it is incontact with the upstand 5 while, at the same time, the first clampsurface 21 is in contact with the underside of the floor slab substructure 2. The clamping apparatus 20 is then fixed in positionrelative to the floor slab sub structure 2 and upstand 5 by tighteningthe wing nut 24 about the threaded shaft 23.

It can be seen from FIG. 6 a that the threaded shaft 23 is parallel tothe outer edge of the building (i.e. parallel to the upstand 5 as itextends away from the floor slab sub structure 2). Due to this alignmentof the threaded shaft 23, it can also be seen from FIG. 6 a that theelongate arm 26 extends parallel to the floor slab sub structure 2.

A U-shaped channel 8 is clamped in position between the elongate fixingelement 12 and the elongate arm 26 using a wing nut 28 and threadedshaft 27. The U-shaped channel 8 can be clamped in position before orafter the clamping apparatus 20 has been attached to the floor slab substructure 2 and upstand 5. The elongate fixing element 12 can be movedto a desired location along the length of the elongate arm 26.

Since the elongate arm 26 extends parallel to the floor slab substructure 2, and since the U-shaped channel 8 is clamped to the elongatearm 26, the U-shaped channel 8 is also aligned parallel to the floorslab sub structure 2, as well as being level with the uppermost surfaceof the upstand 5.

FIG. 6 b shows the arrangement of FIG. 6 a when concrete 10 has beenpoured onto the floor slab sub structure 2 and corrugated sheet 6. Theconcrete is prevented from pouring out of the building by the upstand 5.FIG. 6 c shows the arrangement of FIG. 6 b when the clamping apparatus20 has been removed and the concrete 10 allowed to set. It can be seenthat since the U-shaped channel 8 was aligned parallel to the floor slabsub structure 2 and level with the uppermost surface of the upstand 5,that the level of the concrete 10 is aligned well with the uppermostsurface of the U-shaped channel 8.

FIG. 6 d shows how curtain walling 4 can be attached to the U-shapedchannel 8 in the same manner as described with reference to FIG. 3 c.Since the U-shaped channel 8 is well aligned, the bracket 11 andcurtain-walling section 4 can also be aligned well—i.e. the bracket 11can be aligned such that it is parallel to the level of the concrete 10,and, consequently, the curtain-walling section 4 can be aligned suchthat it is parallel to the upstand 5, and thus the outside of thebuilding.

It will be appreciated that the method and apparatus used to applycurtain-walling to the building described in relation to FIGS. 5 and 6is a vast improvement over the apparatus and method described inrelation to FIGS. 3 and 4. In FIGS. 3 and 4, alignment of the U-shapedchannel depends strongly on the attachment of the U-shaped channel 8 tothe metal mesh 7. If this metal mesh 7 is not level when attachment tothe U-shaped channel 8 is made, the U-shaped channel 8 will not bealigned correctly and will need realignment before the curtain-wallingsections can be attached to their term. In stark contrast, the methodand apparatus according to the present invention allows the U-shapedchannel 8 to be quickly and accurately aligned. The fact that theU-shaped channel 8 is clamped to the elongate arm 26 of a clampingapparatus 20 means that the alignment of the U-shaped channel 8 is notaffected when concrete is poured onto the floor slab sub structure 2.Since alignment of the U-shaped channel 8 using the method and apparatusaccording to the present invention is quick and accurate, time andexpense can be saved when compared with prior art techniques, whererealignment of the U-shaped channel 8 is often required.

It will be appreciated that the guide rail 25 is not essential to theoperation of the clamping apparatus 20. The guide rail only serves toadd rigidity and structural support to the clamping apparatus 20.Similarly, it will be appreciated that the second clamp (e.g. thatcomprising the wing nut 28, threaded shaft 27 and elongate fixingelement 12) need not be moveable along the length of the elongate arm26. However, the movement of the second clamp along the elongate arm 26allows a certain degree of flexibility in the positioning of theU-shaped channel 8, as will be described further below.

As described above it can be seen from the Figures that thesubstantially U-shaped channel 8 is not exactly U-shaped, but hasinwardly facing lips. As stated above, the lips are used to prevent afixing element from moving out of the channel when the fixing elementhas been appropriately positioned in the channel. It will be appreciatedthat the channel need not be U-shaped, but can be of another shape whichdefines a channel for reception of a fixing element. For example, thecross-section of the channel can be substantially triangular,trapezoidal, rectangular etc., the channel having lips to prevent afixing element from moving out of the channel when the fixing elementhas been appropriately positioned in the channel. Such channels arereferred to generally as fixing channels (see for example the fixingchannels manufactured and sold by Ancon Building Products, Sheffield,UK).

An elongate fixing element is a fixing element which has a greaterlength than width. For example, an elongate fixing element may be anelongate piece of metal, such as an abbeysolt. By using an elongatefixing element, the fixing element can be fixed in position in a fixingchannel. To do this, the elongate fixing element is oriented so that itslength is parallel to that of the channel. The elongate fixing elementis then located in the channel. The elongate fixing element is thenrotated such that its length is perpendicular to the length of thechannel, the lips of the fixing channel preventing the fixing elementfrom being removed.

It will be appreciated by one having ordinary skill in the art that theabove embodiments are given by way of example only. One having ordinaryskill in the at will appreciate that various modifications may be madeto the described embodiments without departing from the invention asdefined by the claims that follow.

1. A clamping apparatus, comprising: a first clamp provided with: afirst clamp surface; a second clamp surface; and a substantiallystraight shaft, the first clamp surface and second clamp surface beingarranged to be moveable relative to each other along the shaft to clampan object between the first clamp surface and the second clamp surface,at least one of the clamp surfaces being releasably fixable, and asecond clamp provided on an arm which extends from the second clampsurface, the arm extending in a direction substantially perpendicular tothe shaft.
 2. A clamp as claim in claim 1, wherein the first clampsurface is fixed in position relative to the shaft, and the second clampsurface is moveable relative to the first clamp surface.
 3. A clamp asclaimed in claim 2, wherein the shaft extends from the first clampthrough the second clamp surface.
 4. A clamp as claimed in claim 1,wherein the second clamp is moveable along the arm, in a directionsubstantially perpendicular to the length of the shaft.
 5. A clamp asclaimed in claim 4, wherein the second clamp is moveable along a slotprovided in the arm.
 6. A clamp as claimed in claim 1, furthercomprising a guide rail, the guide rail being substantially straight andparallel to shaft, extending between the first clamp surface and secondclamp surface.
 7. A clamp as claimed in claim 6, wherein the guide railextends from the second clamp surface through the first clamp surface.8. A clamp as claimed in claim 1, wherein the shaft is provided with asecuring element for releasably securing at least one of the clampsurfaces in position when the first clamp is arranged to clamp anobject.
 9. A clamp as claimed in claim 1, wherein the second clampcomprises a shaft which extends through the arm, the shaft beingarranged to engage with a securing element on one side of the arm, andthe shaft being provided with a clamp surface on another side of the armwhich is arranged to clamp an object inbetween the clamp surface and thearm.
 10. A clamp as claimed in claim 9, wherein the clamp surface isprovided by an elongate fixing element.
 11. A clamp as claimed in claim10, wherein the elongate fixing element is shaped to engage with afixing channel.
 12. A clamp as claimed in claim 8, wherein the securingelement is a wing nut.
 13. A method of clamping a fixing channel inposition relative to a floor slab sub structure, comprising: moving atleast one of a first clamp surface and a second clamp surface of a firstclamp along a substantially straight shaft, and releasably fixing the atleast one clamp surface to clamp between the first clamp surface and thesecond clamp surface the floor slab sub structure and an upstandextending from the floor slab sub structure; using a second clamp whichis attached to the first clamp to clamp the fixing channel so that thefixing channel is parallel to the floor slab sub structure and in aposition substantially perpendicular to and away from the shaft.
 14. Amethod as claimed in claim 13, wherein the fixing channel is clamped inposition before the first clamp is used to attach the clamp to the floorslab sub structure and upstand.
 15. A method as claimed in claim 13,wherein the fixing channel is clamped in position after the first clampis used to attach the clamp to the floor slab sub structure and upstand.16. A method as claimed in claim 13, further comprising setting thefixing channel in position before removing the clamp and unclamping thefixing channel.
 17. A method as claimed in claim 16, wherein the fixingchannel is fixed in position using concrete or cement.
 18. A method asclaimed in claim 17, wherein the concrete or cement is poured onto thefloor slab sub structure, the extent to which the concrete or cementflows across the floor slab sub structure being restricted, at least inpart, by the upstand.
 19. A method as claimed in claim 16, wherein acurtain walling section is attached to the fixing channel.
 20. A methodas claimed in claim 19, wherein a curtain walling section is attached tothe bracket.
 21. A method as claimed in claim 16, wherein a curtainwalling section is attached to the fixing channel.
 22. (canceled) 23.(canceled)